The present invention relates to luminaire fixtures and, more particularly, to a luminaire fixture having a vented reflector assembly wherein the vents are overhung by a flange of the upper housing casting.
The dissipation of heat built up in a luminaire utilizing a mercury vapor or high pressure sodium lamp is a problem in the design and construction of such luminaire fixtures. The usual solution to provide necessary heat dissipation is to increase the size of the metal upper housing and the metal reflector assembly such that the necessary characteristics are obtained. However, this is an undesirable feature from a cost of material and a weight and size minimization point of view.
As such luminaires are typically utilized outdoors, another restriction on the design of the fixture is that in order to provide necessary safety in isolating the electrical components of the fixture from contamination and to meet Underwriters' Laboratories (UL) requirements, the compartment housing the ballast must be closed to the atmosphere. Typically in such fixtures the ballast is mounted in the upper housing casting. Accordingly, the reflector and refractor assemblies must be mounted to the upper housing casting in a manner such that the ballast compartment in the upper housing casting is essentially closed so as not to permit sparks or hot particles to escape in the event of a failure of the electrical components.
Accordingly, it is an object of the present invention to provide an outdoor luminaire fixture having improved heat dissipation properties without undue size while providing necessary isolation of the electrical components of the fixture.